Long Living Masternode Quorums (LLMQs) were the solution to the scaling problem associated with the previous masternode quorums. LLMQs only require members of the quorum to transmit and validate individual votes (signature shares). The final result, or recovered signature, is only created and transmitted to the rest of the network once enough votes are collected by a quorum member. Transmitting just the single signature means less strain on CPU, RAM, or other network bandwidth resources. LLMQs provide increased scalability by enabling only one aggregated signature to propagate the entire network. In so doing, this also allowed the quorum sizes to increase which simultaneously increases their security. Ultimately, a valid quorum signature from the masternodes reduces the number of confirmations needed to finalize a transaction, while improving network reliability, stability, and security.
Once LLMQs were created and InstantSend became LLMQ-based, finality of transactions became achievable in about one second. Because the recipient of Dash can immediately spend it the second it is sent to them, they no longer have to worry about funds not settling successfully. Transactions can be made in real-time – for stores, peer-to-peer payments, and any other situation – exactly as they would cash currency. In other words, this allowed the term cryptocurrency to be fully realized in its potential. Most other cryptos are not able to be used as a cash currency. This sets Dash far apart from the crowd and brings utility other coins cannot bring.
LLMQs helped scale InstantSend without sacrificing decentralization or security on the Dash blockchain. In fact, combined with Dash’s ChainLocks feature, LLMQ-based InstantSend made Dash instant while remaining immune to 51% mining attacks. 51% mining attacks are cases in which a bad actor or party reverses transactions that were previously considered “confirmed.” This would allow bad actors to steal previously processed transactions and funds. LLMQs allowed for the InstantSend immediate settlement, while ChainLocks made sure confirmations were confirmed.